中国物理B ›› 2015, Vol. 24 ›› Issue (7): 75204-075204.doi: 10.1088/1674-1056/24/7/075204
• PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES • 上一篇 下一篇
刘相梅, 李奇楠, 李瑞
Liu Xiang-Mei (刘相梅), Li Qi-Nan (李奇楠), Li Rui (李瑞)
摘要: The role of pulse parameters on nanoparticle property is investigated self-consistently based on a couple of fluid model and aerosol dynamics model in a capacitively coupled parallel-plate acetylene (C2H2) discharge. In this model, the mass continuity equation, momentum balance equation, and energy balance equation for neutral gas are taken into account. Thus, the thermophoretic force arises when a gas temperature gradient exists. The typical results of this model are positive and negative ion densities, electron impact collisions rates, nanoparticle density, and charge distributions. The simulation is performed for duty ratio 0.4/0.7/1.0, as well as pulse modulation frequency from 40 kHz to 2.7 MHz for pure C2H2 discharges at a pressure of 500 mTorr. We find that the pulse parameters, especially the duty ratio, have a great affect on the dissociative attachment coefficient and the negative density. More importantly, by decreasing the duty ratio, nanoparticles start to diffuse to the wall. Under the action of gas flow, nanoparticle density peak is created in front of the pulse electrode, where the gas temperature is smaller.
中图分类号: (Plasma simulation)